Go Down

Topic: motor speed control advice for a newbie (Read 271 times) previous topic - next topic

jfox

I am planning to (eventually) build an autonomous rover controlled with an Arduino. I am a total newbie to Arduino and electronics. I've been programming for many years. I expect that the hardware learning curve to be greater than the software learning curve. I don't have any hardware yet, will receive Arduino and some sort of starter kit for Christmas. Will start with learning the basics (blink the LEDs and respond to switches and sensors) and then build upon my knowledge and skills to achieve longer term project goals. I am in the dream/plan/learn stage.

An early goal for the project is to take a cheap RC car and control it with the Arduino. I've seen multiple projects like this so do not expect to have too much difficulty doing this.
I think I'll try controlling the switches in the remote first. Depending on results I may mount the Arduino on the car for more direct control or to add collision avoidance sensors.

I believe that controlling the car's direction won't be very difficult. What I'd like to do after I can control direction is control speed.

Let's assume that the car has no throttle and I am using the remote. I should be able to control the motor speed by toggling the 'go forward' switch quickly. More frequent or longer pulses == more speed. I understand that I may not get very fine control by using the remote, so that's okay initially.

Is this the right approach? Is there a better way? Is this a rudimentary form of PWM?

If the car does have a throttle then it's probably a pot or something similar (newbie here, help me with terms please) on the remote. If this is the case then I can control the throttle by changing the output of the pot, right?

If the above concepts are on track I am sure the code to do these this already exists or is pretty easy to write from scratch. I'm more interested in the viability of the concepts at this point.

Feedback please!

liudr

Welcome! You are very much on track and have the right idea of what PWM is. I got curious after reading your post and opened up my remote control. I thought I had throttle control but it turns out to be just on off. Yes, quickly turning on and off will be PWM and might be not smooth. It is worth a try.

jfox

Thank you for the feedback on PWM. Glad to know that I am headed in the right direction.

What about controlling the throttle if it exists? Would the throttle be some sort of pot or something similar? What is the best way to interface to something like that?

liudr


Thank you for the feedback on PWM. Glad to know that I am headed in the right direction.

What about controlling the throttle if it exists? Would the throttle be some sort of pot or something similar? What is the best way to interface to something like that?


This depends. You will need to open the actual remote control to see if it is a pot. If it is a pot, you could use a digital pot or use arduino PWM with capacitor to output a voltage to replace the pot.

jfox

Got it! Really looking forward to getting started with real hardware.

Will post more questions and ideas as they come up.

Go Up